Add single-dataset loading example

README.md

@@ -52,32 +52,44 @@ The underlying recommendation datasets are public datasets from their original s
 
 Please consult the original dataset sources and their terms before using these files.
 
-## Loading
+## Loading One Dataset
 
-The split files can be read as JSON Lines. For example:
+The three datasets are stored in separate directories. To use only one dataset, download only files from that directory. For example, this loads **Beauty** only and does not download Instruments or Yelp:
 
 ```python
+from huggingface_hub import hf_hub_download
 import json
 import numpy as np
 
-with open("beauty/beauty.train.jsonl") as f:
-    first = json.loads(next(f))
+repo_id = "junchenfu/diger-processed-data"
+dataset = "beauty"
 
-emb = np.load("beauty/Beauty.emb-llama.npy")
-```
+train_path = hf_hub_download(repo_id=repo_id, repo_type="dataset", filename=f"{dataset}/{dataset}.train.jsonl")
+valid_path = hf_hub_download(repo_id=repo_id, repo_type="dataset", filename=f"{dataset}/{dataset}.valid.jsonl")
+test_path = hf_hub_download(repo_id=repo_id, repo_type="dataset", filename=f"{dataset}/{dataset}.test.jsonl")
+map_path = hf_hub_download(repo_id=repo_id, repo_type="dataset", filename=f"{dataset}/{dataset}.emb_map.json")
+emb_path = hf_hub_download(repo_id=repo_id, repo_type="dataset", filename="beauty/Beauty.emb-llama.npy")
 
-You can download files with `huggingface_hub`:
+with open(train_path, encoding="utf-8") as f:
+    first_train = json.loads(next(f))
 
-```python
-from huggingface_hub import hf_hub_download
+with open(map_path, encoding="utf-8") as f:
+    emb_map = json.load(f)
 
-path = hf_hub_download(
-    repo_id="junchenfu/diger-processed-data",
-    repo_type="dataset",
-    filename="beauty/Beauty.emb-llama.npy",
-)
+emb = np.load(emb_path, mmap_mode="r")
+
+print(first_train)
+print(len(emb_map))
+print(emb.shape, emb.dtype)
 ```
 
+For the other datasets, use the corresponding directory and embedding filename:
+
+- Instruments: `instruments/Instruments.emb-llama.npy`
+- Yelp: `yelp/Yelp.emb-llama.npy`
+
+Use `hf_hub_download(filename="...")` for single-dataset loading. Avoid `snapshot_download` unless you intentionally want to download the full repository.
+
 ## Citation
 
 If you use these processed artifacts, please cite the DIGER paper and the original dataset sources.